Exemplary embodiments relate to a negative voltage generator, a decoder which utilizes a negative voltage, a nonvolatile memory device, and a memory system.
Semiconductor memory devices are a vital microelectronic component commonly found in digital logic systems, such as computers, and microprocessor-based applications ranging from satellites to consumer electronics. As such, advances in the fabrication of semiconductor memory devices, including process enhancements and circuit-design-related developments that allow scaling to higher memory densities and faster operating speeds, help establish performance standards for other digital logic families.
Semiconductor memory devices are generally categorized as either volatile memory devices or nonvolatile memory devices. Unlike volatile memory devices, nonvolatile memories are capable of retaining storing data in the absence of supplied power. Nonvolatile memory devices, which include permanent and reprogrammable storage modes, are commonly used for program and microcode storage in a wide variety of applications including computers, avionics, telecommunications, and consumer electronics. An example of a nonvolatile memory device is a flash memory device.
Recently, in response to increasing demand for higher density memory devices, multi-bit (or multi-level) memory devices have been developed in which multiple bits (i.e., two or more bits) are stored in each memory cell. A multi-bit flash memory is an example of such a device.